Sensor apparatus to read film information

ABSTRACT

Sensor apparatus is intended to be used with a film cassette which includes optically readable film information indicia and a viewing aperture for viewing the film information indicia. The sensor apparatus comprises an optoelectronic sensor for reading the film information indicia, and a mount for the optoelectronic sensor complementarily shaped with respect to the viewing aperture to fit only part way into the viewing aperture to critically position the optoelectronic sensor relative to the film information indicia.

CROSS-REFERENCE TO RELATED APPLICATIONS

Reference is made to commonly assigned copending applications Ser. No.07/560,921, entitled "Photographic Film Cassette and Camera Apparatusand Method" and filed July 31, 1990 in the names of David C. Smart andDaniel M. Pagano; and Ser. No. 07/562,501 entitled Film Cassette withBuilt-In Support for Optical Sensor to Read Film Information and filedAug. 2, 1990 in the name of Daniel M. Pagano.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to the field of photography, and inparticular to sensor apparatus intended to be used with a film cassettehaving a built-in support for an optical sensor to read filminformation.

2. The Cross-Referenced Applications

The cross-referenced applications each disclose a film cassette capableof advancing a filmstrip automatically out of a light-tight cassetteshell whether the filmstrip is unexposed, only partly exposed, orsubstantially exposed. The film cassette is characterized in that a filmexposure status indicator can be disposed in any one of three uniqueexposure-related positions comprising an unexposed position forproviding a visible indication that the filmstrip is unexposed, a partlyexposed position for providing a visible indication that the filmstripis only partly exposed, and a fully exposed position for providing avisible indication that the filmstrip is substantially exposed.

More particularly in cross-referenced application Ser. No. 07/560,921,the status indicator and a bar code consisting essentially of a seriesof optically readable photoreflective and non-reflective bits arecoaxially fixed to a film spool rotatable inside the cassette shell toadvance the filmstrip out of the shell. The bar code, when read, can beused to stop rotation of the film spool with the status indicator in itspartly exposed and fully exposed positions.

In cross-referenced application Ser. No. 07/562,501, the film cassetteincludes sensor positioning means fixed to the cassette shell forsupporting a photoreflective type optoelectronic sensor a suitabledistance from the optically readable bits to establish a substantiallyoptimal angle of reflection for the optoelectronic sensor to read thebar code.

SUMMARY OF THE INVENTION

Sensor apparatus is intended to be used with a film cassette whichincludes optically readable film information indicia and a viewingaperture for viewing the film information indicia. The sensor apparatuscomprises an optoelectronic sensor for reading the film informationindicia, and a mount for the optoelectronic sensor complementarilyshaped with respect to the viewing aperture to fit only part way intothe viewing aperture to critically position the optoelectronic sensorrelative to the film information indicia.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a film cassette;

FIG. 2 is an elevation view of the film cassette, illustrating thecassette shell open to reveal a film roll coiled about a film spool;

FIG. 3 is an elevation view similar to FIG. 2, through partly insection;

FIG. 4 is an end view partly in section of the cassette shell, the filmroll and the film spool, illustrating the manner in which the film rollis originally stored on the film spool;

FIGS. 5, 6, and 7 are end views similar to FIG. 4, illustrating themanner in which the film roll is unwound from the film spool;

FIGS. 8 and 9 are elevation views of the film roll and the film spool,illustrating the manner in which the film roll is originally stored onthe film spool;

FIGS. 10 and 11 are elevation views similar to FIGS. 8 and 9,illustrating the manner in which the film roll is unwound from the filmspool;

FIG. 12 is an exploded perspective view of the film spool without thefilm roll;

FIG. 13 is an elevation view partly in section of the film roll and thefilm spool, illustrating the manner in which one of a pair of filmconfining flanges of the spool may be fixed to the spool for concurrentrotation with the spool;

FIG. 14 is an end view of the film cassette, illustrating a filmexposure status indicator in an unexposed position;

FIGS. 15 and 16 are end views similar to FIG. 14, illustrating thestatus indicator moved to partly exposed and fully exposed positions,respectively;

FIG. 17 is a perspective view of the film cassette and camera apparatusincluding respective sensing/blocking members that cooperate with thestatus indicator to prevent loading of the cassette into a loadingchamber when the status indicator is in its partly exposed and fullyexposed positions or only in its fully exposed position;

FIGS. 18 and 19 are schematic views partly in section illustratinginteraction of the sensing/blocking members and the status indicatorwhen the status indicator is in its unexposed position;

FIG. 20 is a schematic view similar to FIG. 19 illustrating interactionof the sensing/blocking members and the status indicator when the statusindicator is in its fully exposed position;

FIG. 21 is a schematic view partly in section of a viewing aperture inthe film cassette and camera apparatus including an optical sensor forreading at the viewing aperture a bar code fixed to the film spool; and

FIG. 22 is an end view of the film cassette including an alternateembodiment of the status indicator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The invention is disclosed as being embodied preferably in a 35 mmstill-picture camera. Because the features of this type of camera aregenerally well known, the description which follows is directed inparticular to elements forming part of or cooperating directly with thedisclosed embodiment. It is to be understood, however, that otherelements not specifically shown or described may take various formsknown to persons of ordinary skill in the art.

The Film Cassette--General

Referring now to the drawings, FIGS. 1, 2 and 12 depict a 35 mm filmcassette 1 comprising a light-tight cassette shell 3 and a film spool 5which is rotatable about an axis X in film unwinding and windingdirections U and W within the cassette shell. The cassette shell 3consists of two shell halves 7 and 9 which are mated along respectivegrooved and stepped edge portions 11 and 13. The mated halves 7 and 9define upper and lower aligned circular openings 15 and 17 for arelatively shorter end piece 19 and a longer opposite open-end piece 21of a spool core or hub 23, and they define a narrow relatively-straightfilm passageway 25 to the exterior of the cassette shell 3. The shorterend piece 19 and the longer open-end pieces 21 of the spool core 23 eachinclude an annular peripheral groove 27 which mates with a correspondingedge portion 29 of the respective openings 15 and 17 in the cassetteshell 3 to rotatably support the film spool 5 for rotation about theaxis X in the film unwinding and winding directions U and W. A knownblack velvet or plush material 31 lines the interior of the filmpassageway 25 to prevent ambient light from entering the filmpassageway.

A roll 33 of 35 mm filmstrip F is coiled about the spool core 23 to formsuccessive film convolutions. As shown in FIGS. 2 and 3, the film roll33 includes an outermost convolution which comprises a film leader 35having a leading or forward end 37, and it includes a next-inwardconvolution 39 coiled behind the outermost convolution. The inner ortrailing end of an innermost convolution 40 of the film roll 33 issecured to the spool core 23 using known attachment means, not shown.See FIG. 13.

A pair of upper and lower identical, very thin, flexible filmconstraining flanges 41 and 43 are coaxially spaced along the spool core23 as shown in FIGS. 1, 2, 8, 12 and 13. The two flanges 41 and 43comprise respective integral disks 45 and 47 and respective integralannular lips or skirts 49 and 51 which circumferentially extend from thedisks. The two disks 45 and 47 cover opposite substantially flat sidesof the film roll 33 which are defined by corresponding oppositelongitudinal edges 53 and 55 of each successive convolution of the filmroll, and they have respective central holes 56 through which the spoolcore 23 coaxially extends to permit rotation of the spool core relativeto the flanges 41 and 43. See FIGS. 12 and 13. Respectivecircumferential gaps 57 are provided in the spool core 23 for supportingthe flanges 41 and 43 at their disks 45 and 47 to permit the flanges tobe independently rotated about the axis X. The two gaps 57 aresufficiently spaced from one another along the spool core 23 to maintainrespective inner faces 45' and 47' of the disks 45 and 47 slightlyspaced from the longitudinal edges 53 and 55 of each successiveconvolution of the film roll 33. See FIG. 13. The annular lips 49 and 51overlap the film leader (outermost convolution) 35 of the film roll 33radially outwardly of the longitudinal edges 53 and 55 of the leader toradially confine the leader to thus prevent it from radially expandingor clock-springing into substantial contact with an interior curved wall58 of the cassette shell 3. A lip-receiving notch 59 is cut in the filmleader (outermost convolution) 35 along its longitudinal edge 55,relatively close to its leading end 37, to receive a peripheral section51' of the annular lip 51. This allows a relatively short edge-section61 of the film leader (outermost convolution) 35 connecting the leadingend 37 and the notch 59 to overlap the annular lip 51 radially outwardlyto thus maintain the leading end spaced a radial distance D from thenext-inward convolution 39 of the film roll 33. See FIGS. 4 and 9. Theleading end 37 has a forward edge 63 inclined from the longitudinal edge53 of the film leader (outermost convolution) 35 to the otherlongitudinal edge 55 of the leader to form a forward-most tip or tab 65of the leader which, like the edge-section 61, overlaps the annular lip51 radially outwardly. See FIGS. 1, 2, 8 and 9.

The two flanges 41 and 43 have a plurality of concentric arcuate slots66 cut in their respective disks 45 and 47 to longitudinally extend inthe film unwinding and film winding directions U and W. Engagement meansin the form of respective hook-like members 67, located on the shorterand longer open-end pieces 19 and 21 of the spool core 23, are normallylocated in the concentric slots 66 for movement along the slots intoengagement with the flanges 41 and 43 responsive to rotation of thespool core relative to the flanges in the unwinding direction U and formovement along the slots out of engagement with the flanges responsiveto rotation of the spool core relative to the flanges in the windingdirection W. See FIGS. 12 and 13. Preferably, each of the hook-likemembers 67 has an end face 67' that is beveled to ease the hook-likemember out of one of the concentric slots 66 responsive to rotation ofthe spool core 23 relative to the flanges 41 and 43 in the windingdirection W, in the possible event the spool core is rotated relative tothe flanges far enough in the winding direction to back the hook-likemember out of the slot.

A film stripper-guide 68 projecting from the interior wall 58 of thecassette half 7 is positioned immediately inward of the inner entrancethe film passageway 25 to be received between the leading end 37 of thefilm leader (outermost convolution) 35 and the next-inward convolution39, close to the forward-most tip 65 of the leader, to pick up theleading end and guide it into the film passageway responsive to rotationof the spool core 23 in the unwinding direction U. See FIGS. 1 and 4-7.The leading end 37 will be advanced over the stripper-guide 68 and intothe film passageway 25, rather than between the stripper-guide and thenext-inward convolution 39, because it is spaced the radial distance Dfrom the latter convolution Thus, as shown in FIG. 4, the leading end 37will be located within range of the stripper-guide 68 due to suchspacing D from the next-inward convolution 39.

When the leading end 37 of the film leader (outermost convolution) 35 isadvanced over the stripper-guide 68 responsive to rotation of the spoolcore 23 in the unwinding direction U, the longitudinal edges 53 and 55of the leader start to gently flex respective arcuate portions of thetwo flanges 41 and 43 away from one another, i.e. farther apart, firstto allow the notch 59 to separate from the lip section 51', and then toallow successive longitudinal sections of the leader to uncoil frombetween the flanges and exit to the outside of the cassette shell 3. SeeFIGS. 10 and 11. The flexing of the flanges 41 and 43 occurs because thefilm width W_(F) between the longitudinal film edges 53 and 55 isslightly greater than the axial spacing A_(S) between the annular lips49 and 51. Moreover, successive convolutions of the film roll 33 have aresistance to transverse bowing that is greater than the resistance ofthe flanges 41 and 43 to be flexed. Two pairs of flat curved bearingmembers 69 project from the interior walls 58 of the respective shellhalves 7 and 9 to lie flatly against successive arcuate portions of thetwo disks 45 and 47 as the flanges 41 and 43 are flexed away from oneanother, to only allow those flange portions separated from the bearingmembers to be flexed farther apart See FIGS. 1, 2 and 4. The bearingmembers 69 are positioned relatively remote from the film passageway 25.Thus, the leader 35 is only allowed to uncoil from between the flanges41 and 43 relatively close to the passageway 25. See FIG. 7.

A film flattening rib 71 projects from the interior wall 58 of thecassette half 9 in the vicinity of the inner entrance to the filmpassageway 25 and the stripper-guide 68 to support successivelongitudinal sections of the film leader 35, beginning with its leadingend 37, substantially flat widthwise as those sections are freed fromthe flanges 41 and 43, to facilitate movement of the leading end intothe passageway. See FIG. 7. The light-trapping plush 31 within the filmpassageway 25 is elevated along the passageway slightly beyond alongitudinal center line L of the passageway. The film flattening rib 71as shown in FIG. 4 projects almost to the center line L in order tosupport successive sections of the film leader 35 substantially flat atthe center line. Preferably, the film-supporting tip or longitudinaledge of the flattening rib 71 is spaced 0.005"-0.030" short of

Two substantially parallel curved film supporting ribs 75 and 76 projectfrom the interior wall 58 of the cassette half 7 to longitudinallyextend from the film flattening rib 71 to part-way between the pair ofbearing members 69 which project from the same wall. See FIGS. 1, 3, and4. The film supporting ribs 75 and 76 longitudinally extend the entirelocation at which the film leader (outermost convolution) 35 can escapethe confinement of the flanges 41 and 43, when the leader axially flexesthe flanges away from one another. The film supporting ribs 75 and 76 asshown in FIG. 3 are positioned to be slightly spaced from the filmleader 35, when the leader is confined within the annular lips 49 and51. Another film supporting rib 77 projects from the interior wall 58 ofthe cassette half 7, opposite the stripper-guide 68. The other rib 77 issubstantially parallel to and shorter than the first-two ribs 75 and 76.All three of the ribs 75-77 longitudinally extend perpendicular to andadjoin the flattening rib 71. See FIG. 1.

When the spool core 23 is initially rotated in the film unwindingdirection U, the two flanges 41 and 43 momentarily tend to remainstationary and the film roll 33, since its inner end is attached to thespool core, will expand radially or clock-spring to force the filmleader (outermost convolution) 35 firmly against the annular lips 49 and51 of the flanges. Generally however, before the film roll 33 can beexpanded radially to the extent a non-slipping relation would be createdbetween the film leader (outermost convolution) 35 and the annular lips49 and 51 as in cited U.S. Pat. Nos. 4,834,306 and 4,848,693, thehook-like members 67 will have moved along the respective slots 66 intoengagement with the two flanges 41 and 43 to fix the flanges to thespool core. Then, further rotation of the spool core 23 will similarlyrotate the flanges 41 and 43. As a result, the leading end 37 of thefilm leader (outermost convolution) 35 will be advanced over the shorterrib 77 and the stripper-guide 68, causing successive arcuate portions ofthe flanges 41 and 43 to be flexed away from one another as shown inFIG. 11. This first allows the notch 59 to separate from the lip section51', and then it allows successive longitudinal sections of the filmleader 35 to exit from between the flanges to the outside of thecassette shell 3. Since the stripper-guide 68 initially picks up theleading end 37 of the film leader 35 close to its forward-most tip 65,the forward edge 63 of the leading end will move against the filmflattening rib 71 as shown in FIG. 6.

When the film leader 35 is thrust through the film passageway 25 to theoutside of the cassette shell 3, the passageway due to the plushmaterial 31 presents some resistance to outward movement of the leader.This resistance causes the leader 35 to further flex the flanges 41 and43 away from one another to, in turn, allow more of the leader to uncoilfrom between the flanges. If the two ribs 75 and 76 were omitted fromthe shell half 9, the leader 35 might uncoil against the interior wall58 of the shell half. As a result, increased torque would be required torotate the spool core 23 in the film unwinding direction U. However, thetwo ribs 75 and 76 serve to severely limit the extent to which theleader 35 can uncoil from between the flanges 41 and 43.

If the spool core 23 is rotated in the film winding direction W aftersome length of the filmstrip F has been advanced from the cassette shell3, the spool core is free to rotate relative to the two flanges 41 and43 because the hook-like members 67 can move along the respective slots66 out of engagement with the flanges. This permits the flanges 41 and43 to be independently rotated in the winding direction W, though at aslower speed than the spool core 23 is rotated in that direction. Eachof the hook-like members 67 may back out of one of the slots 66 and intothe next slot during continued rotation of the spool core 23 in thewinding direction W. At the same time, the filmstrip F will be rewoundonto the spool core 23 between the flanges 41 and 43.

The Film Exposure Status Indicator/Lock-Out Means Of The Film Cassette

FIGS. 2, 3, 12 and 13 depict a film exposure status indicator/lock-outmeans 101 integrally formed with the longer open-end piece 21 of thespool core 23. Respective indicia "PARTIAL" and "EXP" indicating thatthe filmstrip F is only partly exposed, i.e. only some of the availablefilm frames are exposed, and is substantially exposed, i.e. all of thefilm frames are exposed, are printed on a label 103 adhered to thecassette half 9. See FIGS. 14 and 17. An end cap 105 comprising part ofthe cassette shell 3 covers the indicator/lock-out means 101. The endcap 105 has respective circumferential indicator windows 107 and 109aligned with the two indicia "PARTIAL and "EXP" and has separatelock-out windows 111 and 113. The indicator windows 107 and 109 arespaced apart via an arcuate side portion 115 of the end cap 105, and thelock-out windows 111 and 113 are spaced apart via an arcuate sideportion 117 of the end cap. The indicator lock-out means 101 includes anarcuate beveled-edge indicator portion 119 and an arcuate rib-edgelock-out portion 121 having contrasting colors such as red and green.When the indicator/lock-out means 101 is rotationally oriented relativeto the end cap 105 as shown in FIG. 14, it is in an unexposed positionin which the beveled-edge indicator portion 119 is at the lock-outwindows 111 and 113 and the rib-edge lock-out portion 121 is at theindicator windows 107 and 109. At this time, the filmstrip F storedinside the cassette shell 3 is unexposed. When the indicator/lock-outmeans 101 is rotationally oriented relative to the end cap 105 as shownin FIG. 15, it is in a partly exposed position in which the beveled-edgeindicator portion 119 is at the lock-out window 111 and the indicatorwindow 107 and the rib-edge lock-out portion 121 is at the lock-outwindow 113 and the indicator window 109. At this time, the filmstrip Fstored inside the cassette shell 3 is partly exposed. When theindicator/lock-out means 101 is rotationally oriented relative to theend cap 105 as shown in FIG. 16, it is in a fully exposed position inwhich the beveled-edge indicator portion 119 is at the indicator windows107 and 109 and the rib-edge lock-out portion 121 is at the lock-outwindows 111 and 113. At this time, the filmstrip F stored inside thecassette shell 3 is substantially exposed.

The end cap 105 has a central opening 123 aligned with the longeropen-end piece 21 of the spool core 23, and has an integrally formedresilient locking pawl 125 for releasably engaging the longer open-endpiece at respective notches or detents 127, 129 and 131 cut in thelonger open-end piece. When the indicator/lock-out means 101 is in itsunexposed position as shown in FIG. 14, the locking pawl 125 releasablyengages the longer open-end piece 21 at the notch 127. When theindicator/lock-out means 101 is in its partly exposed position as shownin FIG. 16, the locking pawl 125 releasably engages the longer open-endpiece 21 at the notch 129. When the indicator lock-out means 101 is inits fully exposed position as shown in FIG. 16, the locking pawl 125releasably engages the longer open-end piece 21 at the notch 131. Thus,the spool core 23 can be rotationally arrested with theindicator/lock-out means in anyone of the unexposed, partly exposed andfully exposed positions.

The Film Information Disk Of The Film Cassette

A film information disk 141 is coaxially fixed to the shorter end piece19 of the spool core 23. See FIGS. 1, 2, 12 and 21. The information disk141 has an annular array of optically readable information comprising abar code 143 consisting essentially of a series of radially arrangedphotoreflective and non-reflective bits. Details of the bar code and itsrelation to the indicator/lock-out means 101 are disclosed incross-referenced application Ser. No 07/560,921.

An end shroud 145 comprising part of the cassette shell 3 covers theinformation disk 141 except at a central opening 147 and a viewingaperture 149. The central opening 147 allows one to eye-read ormachine-read certain information (not shown) such as film speed, thetotal number of available film frames, etc., printed on the informationdisk 141. The viewing aperture 149 is dimensioned to access one of thephotoreflective or non-reflective bits at a time as the information disk141 is rotated with the spool core 23 in the winding direction W, and islocated a predetermined distance P, e.g. 1 mm, from the disk toestablish a substantially optimal angle of reflection R, e.g. 80°; for aphotoreflective type optoelectronic sensor 151 positioned at the viewingaperture as shown in FIG. 21 when the film cassette is loaded into aphotographic camera including the optoelectronic sensor. Theoptoelectronic sensor 151 comprises a commercially available, compact,reflective photomicrosensor 153 such as OMRON EE-SY120/-SY121/-SY122,manufactured by Omron Tateisi Electronics Co., Osaka Japan, or SHARPGP2504/GP2506/GP2507, GP 2509/GP2510, manufactured by Sharp Corporation,Osaka Japan, and a special mount or holder 155 for the photosensor. Thespecial mount or holder 155 is complementarily shaped with respect tothe viewing aperture 149 to fit only part way into the viewing apertureas shown in FIG. 21. More particularly, the mount 155 has a curvedforward face 156 adapted to be received substantially completely in theviewing aperture 149 in order to be cradled or nested at beveled edges157 of the viewing aperture. In addition, the mount 155 has a flatstabilizing face 159 located rearward of the curved forward face 156 forresting against the end shroud 145 of the cassette shell 3 when thecurved forward face is received substantially completely in the viewingaperture 149 or shown in FIG. 21.

Camera Apparatus

Camera apparatus 201 is shown in FIG. 17 for use with theindicator/lock-out means 101 of the film cassette 1. The cameraapparatus 201 includes a camera body 203 having a loading chamber 205with an entry opening 207 for receiving the film cassette 1 endwise intothe chamber. A release pin 209 is located at the bottom of the loadingchamber 203 for receipt in the central opening 123 of the end cap 123 todisplace the locking pawl 125 from either of the notches 127 or 129. Thenotches 127 and 129 preferably are beveled along their bottom edges tofacilitate displacement of the locking pawl 125 from the notches SeeFIG. 19. Thus, the indicator/lock-out means 101 will be permitted torotate with the spool core 23 in the winding direction W from theunexposed position shown in FIG. 14 to the partly exposed position shownin FIG. 15 and from the partly exposed position to the fully exposedposition shown in FIG. 16.

A sensing/blocking member 211 located within a slot 213 opening into theloading chamber 205 is urged by a helical compression spring 215 topivot clockwise in FIG. 17 about a support pin 217 until a hook-like end219 of the sensing/blocking member protrudes into the loading chamber.In this normal position, the sensing/blocking member 211 is disposed tolocate its hook-like end 219 for abutment with the beveled-edgeindicator portion 119 or the rib-edge lock-out portion 121 at thelock-out window 111 in the end cap 105. See FIGS. 14-16. If the filmcassette 1 is initially inserted into the loading chamber 205, with theindicator/lock-out means 101 in its unexposed or partly exposed positionas shown in FIGS. 14 and 15, the beveled-edge indicator portion 119 atthe lock-out window 111 will contact the hook-like end 219 of thesensing/blocking member 211 to cam or pivot the latter member out of theway of the beveled-edge indicator portion to allow the film cassette tobe further inserted into the loading chamber. See FIGS. 18 and 19.However, should the film cassette 1 be initially inserted into theloading chamber 205, with the indicator/lock-out means 101 in its fullyexposed position as shown in FIG. 16, the rib-edge lock-out portion 121at the lock-out window 111 will be caught by the hook-like end 219 ofthe sensing/blocking member 211 to prevent further insertion of the filmcassette into the loading chamber. See FIG. 20. Thus, camera apparatuswith the sensing/blocking member 211 is intended to receive the filmcassette 1 with fresh unexposed or partly exposed film.

An alternate embodiment of the sensing/blocking member 211 is shown inFIG. 17. In this embodiment, the reference numbers 211', 213', and 219'correspond to the reference numbers 211, 213 and 219. If the filmcassette 1 is initially inserted into the loading chamber 205, with theindicator/lock-out means 101 in its unexposed position as shown in FIG.14, the beveled-edge indicator portion 119 at the lock-out window 113will contact the hook-like end 219' of the sensing/blocking member 211'to cam or pivot the latter member out of the way of the beveled-edgeindicator portion to allow the film cassette to be further inserted intothe loading chamber. However, should the film cassette 1 be initiallyinserted into the loading chamber 205, with the indicator/lock-out means101 in its partly exposed or fully exposed position as shown in FIGS. 15and 16, the rib-edge lock-out portion 121 at the lock-out window 113will be caught by the hook-like end 219' of the sensing/blocking member211' to prevent further insertion of the film cassette into the loadingchamber. Thus, camera apparatus with the sensing/blocking member 211' isintended to receive the film cassette 1 only with fresh unexposed film.

Alternate Embodiment of the Status Indicator/Lock-Out Means of the FilmCassette

FIG. 22 depicts an alternate embodiment of the indicator/lock-out means101 in which, instead of the beveled-edge indicator portion 121 havingcontrasting colors, they are the same color and an indicator tab 301 islocated adjacent the beveled-edge indicator portion. The indicator tab301 as shown in FIG. 22 is not visible when the indicator/lock-out means101 is in its unexposed position. When the indicator/lock-out means 101is in its partly exposed position, the indicator tab 301 is only visiblein the indicator window 107. When the indicator/lock-out means 101 is inits fully exposed position, the indicator tab 301 is only visible in theindicator window 109.

The invention has been described with reference to a preferredembodiment. However, it will be appreciated that variations andmodifications can be effected within the ordinary skill in the artwithout departing from the scope of the invention.

I claim:
 1. Sensor apparatus to be used with a film cassette whichincludes optically readable film information indicia and a viewingaperture for viewing the film information indicia, said sensor apparatuscomprising:an optoelectronic sensor for reading the film informationindicia of the film cassette; and a mount for said optoelectronic sensorcomplementarily shaped with respect to the viewing aperture of the filmcassette to fit only part way into the viewing aperture to criticallyposition the optoelectronic sensor relative to the film informationindicia of the film cassette.
 2. Sensor apparatus as recited in claim 1,wherein said mount has a curved forward face adapted to be receivedsubstantially completely in the viewing aperture of the film cassette inorder to cradle the mount at respective edges of the viewing aperture.3. Sensor apparatus as recited in claim 2, wherein said mount has astabilizing face located rearward of said curved forward face forcontacting the film cassette at its exterior when the curved forwardface is received substantially completely in the viewing aperture of thefilm cassette
 4. Sensor apparatus to be used with a film cassette whichincludes a rotatable disk having optically readable film informationindicia consisting essentially of an annular series of photoreflectiveand non-reflective bits and further includes a fixed viewing aperturefor viewing the respective bits as the disk is rotated, said sensorapparatus comprising:a photoreflective type optoelectronic sensor forreading the film information indicia of the film cassette; and a mountfor said photoreflective type optoelectronic sensor complementarilyshaped with respect to the viewing aperture of the film cassette to fitonly part way into the viewing aperture to critically position thephotoreflective type optoelectronic sensor relative to the rotatabledisk of the film cassette.